Cartons of various sizes, shapes and types, made from various materials, are important throughout commerce and industry in applications too numerous to catalog. One particular example is the food service industry, where such containers are routinely used by the millions to package prepared foods, such as hamburgers, french fries and the like, for convenient handling and transport prior to consumption.
Given the vast demand for such cartons it is imperative that they be produced cheaply, quickly and reliably, while minimizing the need for inspection of the finished product. Due to the further demand for continuously changing carton designs involving different sizes, shapes, features and materials, it is also important that a machine which manufactures such items be readily adaptable to manufacture the new designs and accommodate different materials and features. Finally, the machine itself should be of simple construction, easy to operate and maintain, operate reliably and have a minimum of moving parts.
Although carton fabrication machines have been long in existence, they have generally not satisfied the aforementioned objectives, especially with regard to versatility or simplicity of construction. U.S. Pat. No. 4,861,325 to DiMarzio et al, for example, describes a carton forming machine with distinct limitations imposed on the machine's adaptability to different carton designs. A change to a new carton design might require different adhesive application points. For the DiMarzio machine such a change would entail extensive reconfiguration of the adhesive application system, requiring new parts and significant down time while the machine is rebuilt to handle the new cartons. Similarly, a new carton might require a change in the timing and coordination of the various moving parts of the machine. The DiMarzio machine makes no provision for readily changing the timing, all the moving parts are rigidly synchronized by a single control cam and various linkages and associated followers. Timing changes would entail extensive redesign of the cam and the linkages, requiring essentially a new machine.
The machine disclosed in U.S. Pat. No. 3,648,573 to LeFebvre et al suffers the same problems as the DiMarzio machine and, in addition, is exceedingly complex. The LeFebvre machine has many moving parts such as the belt transfer means, pinch belts, pinch rollers, nip rolls and idler rollers, all of which typically require adjustment, lubrication, inspection and replacement for wear. Of particular complexity is the endless cam track actuating multiple cam follower rods held in a series of bifurcated arms which rotate synchronously with a rotary table. Such complexity leaves significant room for improvement in the state of the art, as is displayed in the present development.